[PATCH AUTOSEL 4.9 10/18] qed: Fix reading wrong value in loop condition
From: Sasha Levin <sashal@kernel.org>
Date: 2018-11-29 06:04:14
Also in:
lkml, stable
Subsystem:
networking drivers, qlogic ql4xxx ethernet driver, the rest · Maintainers:
Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
From: Denis Bolotin <redacted> [ Upstream commit ed4eac20dcffdad47709422e0cb925981b056668 ] The value of "sb_index" is written by the hardware. Reading its value and writing it to "index" must finish before checking the loop condition. Signed-off-by: Denis Bolotin <redacted> Signed-off-by: Michal Kalderon <redacted> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org> --- drivers/net/ethernet/qlogic/qed/qed_int.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/drivers/net/ethernet/qlogic/qed/qed_int.c b/drivers/net/ethernet/qlogic/qed/qed_int.c
index 2adedc6fb6cf..fd19372db2f8 100644
--- a/drivers/net/ethernet/qlogic/qed/qed_int.c
+++ b/drivers/net/ethernet/qlogic/qed/qed_int.c@@ -2135,6 +2135,8 @@ static int qed_int_attentions(struct qed_hwfn *p_hwfn) */ do { index = p_sb_attn->sb_index; + /* finish reading index before the loop condition */ + dma_rmb(); attn_bits = le32_to_cpu(p_sb_attn->atten_bits); attn_acks = le32_to_cpu(p_sb_attn->atten_ack); } while (index != p_sb_attn->sb_index);
--
2.17.1